49 CFR 221.5 : Transportation (§ 1.1 To Parts 1581-1699) — (§ 200.1 To Parts 273-299) — Other Regulations Relating To Transportation (Continued) (§ 200.1 To Parts 273-299) — Federal Railroad Administration, Department Of Transportation (§ 200.1 To Parts 273-299) — Rear End Marking Device - Passenger, Commuter And Freight Trains (§ 221.1 To Appendix C To Part 221) — General (§ 221.1 To § 221.11) — Definitions.